In modern communication networks, scheduling of shared data channels is a matter of great relevance as it is responsible for the correct distribution of bandwidth among a number of services and communications established upon a channel. This distribution determines the amount of time a packet has to wait on a transmission queue, and thus, the latency suffered in a communication and the quality of the final user experience.
Not all services or traffic types have the same tolerance to latency. Real-time communications usually require lower and more homogeneous latency values, while the transfer of greater amounts of static data allows looser requirements. For this reason, most network architectures provide some kind of system which allows the association of a certain degree of priority to a packet, depending on the type of traffic it carries.
A correct priority allocation, and the consequent priority-dependant handling of data packets, shapes a problem that has been solved to some extent, with different degrees of success, by a number of communication protocols and inventions.
Making use of the means provided by different communication protocol standards, a number of inventions have tried to optimize the performance of the priority allocation system. US 2006/153216-A1 uses information about the current state of the network to generate an adaptive schedule. This way, it reorganizes the priorities of the different packets that are present in the system taking into account the mobile station's scheduling downlink transmission rate and a delay factor that represents the staleness of the queued data. Specifically, this method seeks to improve the quality offered to Voice-over-IP services, although it demands the resources needed to provide a constant supervision of the network state.
US 2005/288050-A1 provides a different approach to the same matter of improving user experience through latency reduction. In this case, it focuses on PTT (Push-to-talk) communications, sending packets belonging to a time-sensitive kind of traffic through a signalling channel.
Differential data handling depending on the kind of carried traffic extends to other communication aspects, such as handover process in cellular networks. An example of traffic-type-dependant hand-over can be found in WO 2006/062306-A1.
However, in all of these documents, the different systems perform a generic characterization of the services that are present on the network. By taking into account only the type of traffic that is being carried, any aspect related to the characteristics of a single communication is ignored. Thus, the scheduling satisfies only partially the communication needs, allowing further improvements of the user experience.